1. Field of the Invention
The present disclosure relates to rotary blades, and more particularly to track and balance adjustments to rotary blades.
2. Description of Related Art
Aircraft rotary blades are subject to balance and track variation that subjects the vehicle to vibration. Balance relates to the relative weight of the blades at the hub while track relates to the tendency of a blade to depart from the path of its predecessor during rotation. Track and balance can change over time owing to blades changes over time, such as mass or aerodynamic changes due to wear and erosion or stiffness change due to repeated loading cycles during service. Blade track and balance can also change as a result of maintenance or service, such as when one or more blades of a blade set are replaced. As a result, vibration associated with track and balance error can reach a point where aircraft performance degrades or crew fatigue from exposure to vibration becomes excessive. Structural damage to the aircraft can also result if corrections are not made.
Track and balance problems are typically addressed through a rotor trimming process. Rotor trimming involves physically adjusting one or more components associated with the blade that influence blade track or balance, such as weights, tabs or pitch control rods. Since these components cooperate to define track and balance for a blade, adjustments are interdependent as the performance change resultant from any one adjustment is influenced by the settings of the others. For that reason, rotor trimming typically involves the use of an analysis tool that defines a set of adjustments for the track and balance condition of a given aircraft.
Because one type of adjustment can be more complex, time consuming, or influential than another, conventional analysis tools allow the user to pre-select a subset of adjustments prior to the analysis tool generating an adjustment solution. While this provides the user flexibility, such as improving performance in view of a pre-defined period within which the aircraft has been made available for maintenance, it can also obscure the tradeoffs associated with constraining the adjustment solution to a subset of the otherwise available adjustment alternatives. Different types of adjustments can cause change performance in different ways. Consequently, it can be difficult for the user to understand how a given constraint effects the expected improvement in comparison to an unconstrained and/or differently constrained adjustment solution.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for methods and systems for visualizing alternative adjustments for changing aircraft rotor track and balance performance. The present disclosure provides a solution for these problems.